The TAB Guide to Vacuum Tube Audio:
Understanding and Building Tube Amps
Vacuum tubes

Welcome to the VacuumTubeAudio.info Web site. Please also see the McGraw-Hill Web site for more information on this title.

Cover photo of Vacuum Tube Audio book

• Incorporate the "tube sound" into your home audio system

• Build your own vacuum tube audio amplifiers from the chassis up

• Follow along with do-it-yourself projects

• Detailed schematic drawings and parts lists provided

• Learn construction techniques for a variety of audio projects

• Tweak classic RCA designs for a custom-built project

• Enjoy the unique attributes of the famed "tube sound"

• Bring back "appointment listening" and have some fun doing it

• Supporting information and downloadable documents available from this web site

• ISBN 978-0-07-175321-0, suggested list price $40.00 USD

• Check this web site periodically for new projects, updates, corrections, and errata

About the Book

Learn how to work with vacuum tubes and construct high-quality audio amplifiers on your workbench with help from this hands-on, do-it-yourself resource. The TAB Guide to Vacuum Tube Audio: Understanding and Building Tube Amps explains tube theory and construction practices for the hobbyist. Seven ready-to-build projects feature step-by-step instructions, detailed schematics, and layout tips. You'll also find out how to tweak the projects, each based on a classic RCA design, for your own custom-built amp. Coverage includes:

• Principles and operational theory behind vacuum tubes
• Tube nomenclature, applications, and specifications
• Circuit layout, connections, and physical construction
• Finding and selecting the right components for the project
• Power supplies for vacuum tube circuits
• Preamplifier and power amplifier circuits
• Performance measurement
• Safety, maintenance, and troubleshooting procedures
• Tips on building your own tube-based system and have fun doing it

For more detailed information about the book see the Table of Contents and the Preface.

This book is intended for hobbyists interested in adding the tube sound to their audio system. Readers looking for high-performance audiophile books are urged to consider the McGraw-Hill books by Morgan Jones.

About the Author

Jerry C. Whitaker is Vice President for Standards Development at the Advanced Television Systems Committee (ATSC) in Washington, D.C. ATSC is an international standards development organization focused on advanced digital television systems. Mr. Whitaker was previously President of Technical Press, a consulting company based in the San Jose (CA) area. Mr. Whitaker has been involved in various aspects of the electronics industry for over 30 years, with specialization in communications. Current book titles include the following:

• Editor-in-Chief, Standard Handbook of Video and Television Engineering, 4th ed., McGraw-Hill, 2002
• Editor-in-Chief, Standard Handbook of Audio and Radio Engineering, 2nd ed., McGraw-Hill, 2001
• Editor-in-Chief, Standard Handbook of Broadcast Engineering, McGraw-Hill, 2005
• Author, DTV Handbook, 4th ed., McGraw-Hill, 2006
• Editor, Television Receivers, McGraw-Hill, 2001

Mr. Whitaker has lectured extensively on the topic of electronic systems design, installation, and maintenance. He is the former editorial director and associate publisher of Broadcast Engineering and Video Systems magazines, and a former radio station chief engineer and television news producer.

Mr. Whitaker is a Fellow of the Society of Broadcast Engineers and an SBE-certified Professional Broadcast Engineer. He is also a fellow of the Society of Motion Picture and Television Engineers.

About this Site

This site supports The TAB Guide to Vacuum Tube Audio in a number of ways, including the following:

• Parts lists for the projects described in the book as downloadable Microsoft Word or Excel files
• PWB layout resources
• Additional supporting information and commentary on the projects contained in the book
• Corrections and errata from the first printing
• Additional audio projects using vacuum tubes
• Other interesting stuff relating to vacuum tube audio applications

Corrections and Errata

Unfortunately, errors can creep into a book as it works its way through the writing, editing, production, and printing process. The following items are known issues from the first printing:
• Page 56, Figure 3.5. Two traces are given for three different cathode temperatures. The upper curve for each trace should be dashed, as described in the figure cutline. This replacement figure shows the dashed lines correctly.
• Page 61, first equation on the page: some weird font issue is at play here. The equation should read mu = delta Eb divided by delta Ec1.
• Page 61, fourth equation (total cathode current of an ideal triode) is missing the quantity K (a constant determined by tube dimensions). The quantity inside the brackets is multiplied by K. When K = 1, the term falls out. The corrected page 61 equations are shown here.
• Page 69, Figure 3.17; disregard the dot on the plate (no idea where that came from).
• Page 73, at the bottom of the page the last line says “heather-cathode”; it should read “heater-cathode”.
• Page 191, the last sentence on the page explains that pins 3 and 6 of the 5651A should not be used; the sentence reads "5615A" but should read "5651A".
• Page 202, the text describing the Final Power Supply Design refers to an "R24"; it should be "R23" (there is no R24 on the parts list or on the schematic).
• Page 262, Figure 10.5, the terminal post "RVHa" should read "5VHa."
• Page 311, paragraph 7 (counting the numbered list), the third sentence reads "Table 8.7 list typical..."; it should read "Table 8.6..."
• Page 312, Figure 12.11 lists the tube type for V2 incorrectly as "7876." This, of course, should be 7868 as described in Chapter 11.

My apologies for these errors. If you see anything else that doesn't look right, please let the author know.

A Personal Comment

A funny thing happened after I finished the book and put a couple of the projects (the stereo preamp and the 25 W stereo amplifier) in my home office: I began collecting (well, recollecting) vinyl records.

Collection of vacuum tube audio gear

Regretting it now, I got rid of my LP collection many years ago (OK, decades). CDs were new and modern and convenient and sounded better...or so it seemed.

Viewed with some perspective now, there were some very good vinyl pressings, and some bad ones too. Fortunately for tube enthusiasts, many record labels have begun re-issuing 180 gram vinyl LPs. Between the newly issued and old stock records, the selection of LPs available today is not bad.

So, after collecting some LPs, I began playing them. Much to my surprise my wife (and sometimes even the kids) sat down to listen. It has since become a bit of a ritual to pour some good wine (not for the kids, of course) and put on an LP. There is a certain appeal in listening to a great classic LP out loud—not just earbuds—in a group setting.

The ultimate endorsement came when my wife suggested I move the equipment to the living room so we can turn it up really loud.

Tube Talk at NAB

Each year, the National Association of Broadcasters holds its annual convention in Las Vegas. During the show, more than a hundred highly technical presentations are given on leading audio, video, and transmission technologies. I have attended the NAB Convention for the past 30 years, and given perhaps two dozen talks. In 2012, I had the opportunity to do a short presentation on the topic of vacuum tubes and vinyl records at the SBE Ennes Conference. The presentation was intended as a broad overview of the subject matter. The presentation was titled "The Tube Sound: Fact or Fiction?" I hope you enjoy it.

Update: At the invitation of the Wisconsin Broadcasters Association, I gave an expanded version of the NAB talk at a Society of Broadcast Engineers meeting during the WBA Broadcasters Clinic, October 9-11, 2012, in Madison. This version goes into a little more detail, and led some interesting question-and-answer discussion afterward. (download Acrobat file)